Waste materials which contain combustible constituents can be gasified in a fluidized state in a gasification reactor which is supplied with an oxygen-containing gas. A gas-solids mixture can be supplied from the upper region of the gasifying reactor to a separator. Dust-containing gas and separated solids can be separately withdrawn from the separator, and the separated solids can be recycled at least in part to the lower region of the gasification reactor.
U.S. Pat. No. 4,469,050 describes the combustion or gasification of this type of carbonaceous material or waste material in a circulating fluidized bed. The reaction takes place in a fluidized state in a reactor, which is succeeded by a cyclone separator. The separated solids from the cyclone are recycled at least in part to the lower region of the reactor.